Temporal Distribution And Composition Of Phytoplankton In The Southern Part Of Caspian Sea In Iranian Waters From 1994 To 2007

Simple item page
dc.contributor.authorKhenari, Ali Ganjian
dc.date.accessioned2018-07-30T07:34:24Z
dc.date.available2018-07-30T07:34:24Z
dc.date.issued2011-06
dc.description.abstractCaspian Sea is the largest inner water body on the earth underwent sharp changes in its ecosystem during the recent decades of the twenty century. They were caused by natural eg. transgression of the sea level, climate change, increase of fresh water inflow and anthropogenic factors eg. pollution, invasion of ctenophore Mnemiopsis leidyi and illegal fishing for sturgeons at sea. All that led to significant change in hydrological regime; modify the food base, abundance and biomass of biological resources and bio-productivity of the sea. Long-term qualitative and quantitative characteristics of phytoplankton community structure and biomass were investigated in from 1994 to2007. During the study period, 4556 samples of phytoplankton were collected during 33 cruises in the southern part of the Caspian Sea (SCS). A total of 334 species (88 genera) of phytoplankton were identified in the SCS, which comprised of Bacillariophyta, Chlorophyta, Cyanophyta, Pyrrophyta, Euglenophyta, Chrysophyta, Xanthophyta and Cryptophyta. Bacillariophyta and Pyrrophyta were present in all ecological groups. The phytoplankton ecological groups were fresh water species (34%), fresh – brackish – water species (18%), brackish-water species (14%), brackish-marine-water species (4%), marine species (8%) and other species (22%). The dominant groups of phytoplankton from 1994 to 2007 were Bacillariophyta which constituted the major cell abundance and biomass (37 % and 52%, respectively). The highest annual mean phytoplankton cell abundance and biomass were 249.1×106 ± 22.4×106 cells/m3 and 1034.17±117.81 mg/m3, respectively; and higher population was due to the presence of Pyrrophyta, Bacillariophyta and Cyanophyta between 2001–2002. The cell abundance and biomass of phytoplankton population showed significant difference in years 1994-2007 (p<0.001). The maximum cell abundance (9.7 ×106 cells / m3) and biomass (83.8 mg/m3) were observed in brackish-water and marine water forms, respectively. Long-term changes of cell abundance and biomass in five ecological groups and dominant species were observed in different years. In 2001-2002, the dominant phytoplankton were Exuviella cordata and Rhizosolenia fragilissima; and high density was due to Bacillariophyta and Pyrrophyta in winter. In 1999-2007, after the invasion of ctenophore Mnemiopsis leidyi, higher cell abundance was no longer recorded in spring but in winter and autumn; while higher biomass shifted from summer to winter and spring. High diversity index of phytoplankton was associated with high level of transparency and salinity.en_US
dc.identifier.urihttp://hdl.handle.net/123456789/6069
dc.language.isoenen_US
dc.publisherUniversiti Sains Malaysiaen_US
dc.subjectLong-term qualitative and quantitative characteristicsen_US
dc.subjectphytoplankton community structure and biomass 1994 to2007en_US
dc.titleTemporal Distribution And Composition Of Phytoplankton In The Southern Part Of Caspian Sea In Iranian Waters From 1994 To 2007en_US
dc.typeThesisen_US
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Pusat Pengajian Sains Kajihayat - Tesis